Solid-state imaging device, method of manufacturing solid-state imaging device, and electronic apparatus

ABSTRACT

A solid-state imaging device includes pixels each having a photoelectric conversion element for converting incident light to an electric signal, color filters associated with the pixels and having a plurality of color filter components, microlenses converging the incident light through the color filters to the photoelectric conversion elements, a light shielding film disposed between the color filter components of the color filters, and a nonplanarized adhesive film provided between the color filters and the light shielding film.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/431,899, filed Feb. 14, 2017, which is a continuation of U.S.application Ser. No. 15/294,425, filed Oct. 14, 2016, which is acontinuation of U.S. application Ser. No. 15/078,146, filed Mar. 23,2016, now U.S. Pat. No. 9,508,767, which is a continuation of U.S.patent application Ser. No. 14/976,905, filed Dec. 21, 2015, now U.S.Pat. No. 9,461,081, which is a continuation of U.S. patent applicationSer. No. 14/277,383, filed May 14, 2014, now U.S. Pat. No. 9,253,456,which is a continuation of U.S. patent application Ser. No. 13/548,900,filed Jul. 13, 2012, now U.S. Pat. No. 8,767,108, which is acontinuation-in-part of U.S. patent application Ser. No. 13/362,722,filed Jan. 31, 2012, now U.S. Pat. No. 8,742,525, which claims priorityto Japanese Patent Application Nos. JP 2011-055631 and JP 2012-044006,filed Mar. 14, 2011, and Feb. 29, 2012, respectively, the entiredisclosures of which are hereby incorporated herein by reference.

BACKGROUND

The present technology relates to a solid-state imaging device, a methodof manufacturing a solid-state imaging device, and an electronicapparatus.

CCD (charge coupled device) solid-state imaging devices and CMOS(complementary metal oxide semiconductor) solid-state imaging device arein widespread use in digital cameras and video cameras. Thesesolid-state imaging devices are roughly classified into two groups interms of the direction of the light incident on a light receiving unit.

One of them includes solid-state imaging devices that receive lightincident on the front side of the semiconductor substrate on which awiring layer is formed. The other group includes the so-calledback-illuminated-type solid-state imaging devices that receive lightincident on the back side of the semiconductor substrate on which nowiring layer is formed.

These solid-state imaging devices have a light shielding film forblocking light between pixels to improve sensitivity and prevent colormixture. There is a demand for a solid-state imaging device with furtherimproved image quality and sensitivity and with further suppressed colormixture. Further miniaturization will degrade the overlay accuracybetween layers, especially between a light shielding film, colorfilters, and microlenses, with a significant effect on the colormixture.

To reduce the height of the solid-state imaging device and to improveoverlay accuracy of the light shielding film and color filters, a lightshielding film for reducing the color mixture with the adjacent pixelsis formed on the same plane as the color filters in the solid-stateimaging device of Japanese Unexamined Patent Application Publication No.2010-85755, for example.

SUMMARY

There is a problem, however, with the technique disclosed by JapaneseUnexamined Patent Application Publication No. 2010-85755 that the colorfilters are easily detached from the semiconductor substrate because thecolor filters are formed on the light shielding film and semiconductorsubstrate.

It is desirable to provide a solid-state imaging device and a method ofmanufacturing a solid-state imaging device that can suppress thedetachment of color filters.

It is also desirable to provide an electronic apparatus provided withsuch a solid-state imaging device.

A solid-state imaging device according to an embodiment of the presenttechnology includes pixels each having a photoelectric conversionelement for converting incident light to an electric signal, colorfilters associated with the pixels and having a plurality of colorfilter components, microlenses for converging the incident light throughthe color filters onto the photoelectric conversion elements, a lightshielding film disposed between the color filter components of the colorfilters, and a nonplanarized adhesive film provided between the colorfilters and the light shielding film.

In the solid-state imaging device according to the embodiment of thepresent technology, the detachment of color filters can be suppressed bythe nonplanarized adhesive film disposed between the color filters andthe light shielding film.

A method of manufacturing a solid-state imaging device according to anembodiment of the present technology includes forming pixels each havinga photoelectric conversion element for converting incident light to anelectric signal, forming a light shielding film to be provided between aplurality of color filter components of color filters, depositing anonplanarized adhesive film on the light shielding film, forming thecolor filters on the adhesive film between the light shielding films,and forming on the color filters microlenses for converging the incidentlight through the color filters onto the photoelectric conversionelements.

An electronic apparatus according to an embodiment of the presenttechnology includes the above-mentioned solid-state imaging device, anoptical lens, and a signal processing circuit.

According to the embodiments of the present technology, the detachmentof color filters can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a solid-state imaging device according to a firstembodiment;

FIG. 2 is a cross-sectional view of the solid-state imaging deviceaccording to the first embodiment;

FIGS. 3A to 3F illustrate steps of manufacturing the solid-state imagingdevice according to the first embodiment;

FIG. 4 is a cross-sectional view of a solid-state imaging deviceaccording to a second embodiment;

FIGS. 5A and 5B illustrate steps of manufacturing the solid-stateimaging device according to the second embodiment;

FIG. 6 is a cross-sectional view of a solid-state imaging deviceaccording to a third embodiment;

FIGS. 7A to 7D illustrate steps of manufacturing the solid-state imagingdevice according to the third embodiment;

FIG. 8 is a cross-sectional view of a solid-state imaging deviceaccording to a fourth embodiment;

FIGS. 9A to 9D illustrate steps of manufacturing the solid-state imagingdevice according to the fourth embodiment;

FIG. 10 is a cross-sectional view of a solid-state imaging deviceaccording to a fifth embodiment;

FIGS. 11A and 11B illustrate steps of manufacturing the solid-stateimaging device according to the fifth embodiment;

FIG. 12 is a cross-sectional view of a solid-state imaging deviceaccording to a sixth embodiment;

FIGS. 13A to 13C illustrate steps of manufacturing the solid-stateimaging device according to the sixth embodiment;

FIG. 14 is a cross-sectional view of a solid-state imaging deviceaccording to a seventh embodiment;

FIGS. 15A and 15B illustrate steps of manufacturing the solid-stateimaging device according to the seventh embodiment;

FIG. 16 is a cross-sectional view of a solid-state imaging deviceaccording to an eighth embodiment;

FIGS. 17A and 17B illustrate steps of manufacturing the solid-stateimaging device according to the eighth embodiment;

FIG. 18 is a cross-sectional view of a solid-state imaging deviceaccording to a ninth embodiment;

FIGS. 19A to 19D illustrate steps of manufacturing the solid-stateimaging device according to the ninth embodiment;

FIG. 20 is a cross-sectional view of the solid-state imaging deviceaccording to a tenth embodiment;

FIGS. 21A to 21D illustrate steps of manufacturing the solid-stateimaging device according to the tenth embodiment;

FIGS. 22A and 22B are cross-sectional views of a solid-state imagingdevice according to an eleventh embodiment;

FIGS. 23A to 23C show a light shielding film according to the eleventhembodiment;

FIGS. 24A to 24F illustrate steps of manufacturing the light shieldingfilm according to the eleventh embodiment;

FIGS. 25A to 25F illustrate steps of manufacturing the microlensaccording to the eleventh embodiment;

FIGS. 26A to 26D are cross-sectional views of a solid-state imagingdevice according to the eleventh embodiment;

FIG. 27 is another cross-sectional view of the solid-state imagingdevice according to the eleventh embodiment; and

FIG. 28 illustrates an electronic apparatus according to a twelfthembodiment.

DETAILED DESCRIPTION OF EMBODIMENTS First Embodiment

FIG. 1 is a schematic block diagram showing an exemplary solid-stateimaging device 100 according to a first embodiment of the presenttechnology. The solid-state imaging device 100 shown in FIG. 1 includesa substrate 111 made of silicon, a pixel section 113 including aplurality of pixels 112 arranged in an array on the substrate 111, avertical driving circuit 114, column signal processing circuits 115, ahorizontal driving circuit 116, an output circuit 117, and a controlcircuit 118.

The pixel section 113 includes a plurality of pixels 112 regularlyarranged in a two-dimensional array. The pixel section 113 includes aneffective pixel region that actually receives incident light, amplifiesthe signal charge generated by photoelectric conversion from theincident light, and outputs the amplified signal charge to a columnsignal processing circuit 115, as well as a black reference pixel region(not shown) for outputting the optical black to be used as a referenceblack level. The black reference pixel region is normally formed in aperiphery of the effective pixel region.

A pixel 112 includes a photodiode as a photoelectric conversion element(not shown) and a plurality of pixel transistors (not shown). Aplurality of pixels 112 are regularly arranged in a two-dimensionalarray on the substrate 111. The plurality of pixel transistors mayinclude four MOS transistors including a transfer transistor, resettransistor, selection transistor, and amplification transistor, or mayinclude the above three transistors excluding the selection transistor.

According to a vertical synchronization signal, horizontalsynchronization signal, and a master clock, the control circuit 118generates clock signals and control signals to be used as referencesignals for operations of the vertical driving circuit 114, columnsignal processing circuits 115, and horizontal driving circuit 116. Thecontrol circuit 118 uses the clock signals and control signals tocontrol the vertical driving circuit 114, column signal processingcircuits 115, and horizontal driving circuit 116.

The vertical driving circuit 114 is formed of, for example, shiftregisters and selectively scans the pixels 112 sequentially row by rowin the vertical direction. The vertical driving circuit 114 suppliespixel signals based on the signal charges generated in accordance withthe amounts of light received by the photoelectric conversion elementsof the pixels 112 to the column signal processing circuits 115 throughvertical signal lines 119.

The column signal processing circuits 115 correspond to the columns of,for example, pixels 112 and perform for the associated pixel columnssignal processing such as denoising and signal amplification for thesignals output from one row of pixels 112 on the basis of the signalsfrom the black reference pixel region. A horizontal selection switch(not shown) is provided between the output stage of the column signalprocessing circuit 115 and the horizontal signal line 120.

The horizontal driving circuit 116 is formed of shift registers, forexample. The horizontal driving circuit 116 sequentially outputshorizontal scanning pulses to select the column signal processingcircuits 115 in sequence and cause each of the column signal processingcircuits 115 to output a pixel signal to the horizontal signal line 120.

The output circuit 117 processes the pixel signals sequentially suppliedfrom the column signal processing circuits 115 through the horizontalsignal line 120 and outputs the processed signals to an externalapparatus (not shown).

Referring now to FIG. 2, the solid-state imaging device 100 will bedescribed in detail.

As shown in FIG. 2, the solid-state imaging device 100 according to thepresent embodiment includes a substrate 111, a wiring layer 26 formed onthe front side of the substrate 111, a support substrate 14, colorfilters 15 formed on the back side of the substrate 111 with aninsulator film 18 therebetween, and microlenses 16.

The substrate 111 is a semiconductor substrate made of silicon. Thesubstrate 111 has a thickness of 3-5 μm. On the substrate 111, aplurality of pixels 112 each including a photoelectric conversionelement 11 and a plurality of pixel transistors Tr forming a pixelcircuit section are formed in a two-dimensional matrix. Although notshown in FIG. 2, peripheral circuit sections are formed in theperipheral regions of the pixels 112 formed on the substrate 111.

In the photoelectric conversion element 11, which is a photodiode, forexample, a signal charge is generated and accumulated in accordance withthe amount of light received from the incident light.

The pixel transistor Tr has a source/drain region (not shown) formed onthe front side of the substrate 111 as well as a gate electrode 128formed on the front side of the substrate 111 with a gate insulatingfilm 129 therebetween.

An element separation region 24 including a high-concentration impurityregion is formed between adjacent pixels 112, extending from the frontside to the back side of the substrate 111. The pixels 112 areelectrically separated from each other by the element separation region24.

The wiring layer 26 is formed on the front side of the substrate 111 andhas wirings 261 arranged in a plurality of layers (three layers in FIG.2) with an interlayer insulator film 27 therebetween. The pixeltransistor Tr forming part of the pixel 112 is driven through thewirings 261 formed in the wiring layer 26.

The support substrate 14 is formed on the surface of the wiring layer 26opposite to the surface facing the substrate 111. The support substrate14 is formed in order to ensure the strength of the substrate 111 in themanufacturing stage. The support substrate 14 is formed of a siliconsubstrate, for example.

The color filters 15 are formed on the back side of the substrate 111with an insulator film 18 therebetween and include first, second, andthird color filter components, for example, for each pixel. For example,the first, second, and third color filter components may be green, red,and blue filter components, respectively, but are not limited theretoand may be any color filter components. Instead of the color filtercomponents, other filter components may be used such as transparentresins, for example, that transmit visible light or ND filterscontaining carbon black pigments in transparent resins to attenuatevisible light.

Light with the desired wavelength is transmitted through the colorfilters 15 and enters the photoelectric conversion elements 11 in thesubstrate 111.

A light shielding film 17 is provided between the color filtercomponents of the color filters 15. An adhesive film 19 is formedbetween the light shielding film 17 and the color filters 15 and betweenthe insulator film 18 and the color filters 15.

The light shielding film 17 is provided in order to reduce color mixturecaused by the leakage of incident light to the adjacent photoelectricconversion elements 11. The light shielding film 17 is formed of anelectrically conductive material or an organic material with black colormaterial scattered therein.

The adhesive film 19 is provided between the color filters 15 and thelight shielding film 17 and between the color filters 15 and theinsulator film 18 in order to adhere the color filters 15 to the lightshielding film 17 and the insulator film 18. The adhesive film 19 is anonplanarized transparent film with good adhesion to the color filters,oxide film, nitride film, and metal. Preferably, the adhesive film 19 ismade of a thermoplastic resin material having thermal fluidity in acertain temperature region such that the irregularities of applicationthereof due to the rugged surface of the underlying layer (in this case,light shielding film 17 and insulator film 18) are reduced in a thermaleffect process, as well as a thermosetting property in a final heattreatment process.

Examples of the above-mentioned resin material include organic filmsmade of acrylic resin, phenolic resin, siloxane resin, or copolymerresin thereof, and epoxy resin, for example. More specifically,“TMR-C006” available from TOKYO OHKA KOGYO CO., LTD., Japan may be used,for example. Here, the case where epoxy resin is used as a curable groupor a curing agent is included in this example. Further, as the adhesivefilm 19, an insulator film, which is mainly composed of silicon (Si),carbon (C), and hydrogen (H), such as an inorganic single film composedof SiCH, SiCOH, or SiCNH, for example may be used.

The adhesive film 19 is formed by making use of the shape of the lightshielding film 17. More specifically, since the adhesive film 19 isdeposited after the light shielding film 17 is formed, the adhesive film19 is formed on the upper surface and side walls of the light shieldingfilm 17.

It is favorable to form the adhesive film 19 in such thickness that atleast part of the color filter 15 is formed to be positioned lower thanthe light shielding film 17 which is formed to correspond to each pixel.That is, the adhesive film 19 is formed to have the thickness T2 whichsatisfies T2<T1, where T1 is the film thickness of the light shieldingfilm 17. Here, the adhesive film 19 may be formed by patterning andetching using lithography so as to cover only the upper surface and theside walls of the light shielding film 17.

Next, a method of manufacturing the solid-state imaging device 100 willbe described. The method of manufacturing the solid-state imaging device100 includes forming pixels 112 each having a photoelectric conversionelement 11 for converting incident light to an electric signal, forminga light shielding film 17 to be disposed between a plurality of colorfilter components of color filters 15, depositing a nonplanarizedadhesive film 19 on the light shielding film 17, forming the colorfilters 15 on the adhesive film 19 between the light shielding films 17,and forming on the color filters 15 microlenses 16 for convergingincident light through the color filters 15 onto the photoelectricconversion elements 11.

Referring now to FIGS. 3A to 3F, the method of manufacturing thesolid-state imaging device 100 will be described in detail. The steps offorming the pixels 112 are similar to those in the related art andtherefore description thereof will be omitted.

As shown in FIG. 3A, an insulator film 18 is deposited on aphotoelectric conversion element 11 using a CVD, ALD, or PVD method orthe like.

Next, a film 171 (in this case, metal) is deposited to form a lightshielding film 17 (FIG. 3B). Subsequently, the film 171 is patterned bylithography to form in the film 171 apertures for pixels 112 and thenetched to form the light shielding film 17 (FIG. 3C).

After the light shielding film 17 is formed as shown in FIG. 3D, anadhesive film 19 is deposited or applied using a spin coating process,spray coating process, slit coating process, or the like. Opticallyefficient color filters 15 with a thickness of approximately 100 nm to 1μm are formed on the adhesive film 19 (FIG. 3E).

Microlenses 16 are formed on the color filters 15 (FIG. 3F).

In the solid-state imaging device 100 according to the presentembodiment, the nonplanarized adhesive film 19 provided between thecolor filters 15 and light shielding films 17 as described above cansuppress the detachment of color filters.

Further, part of the color filer 15 is embedded in the layer of thelight shielding film 17, enabling reduction in height of the solid-stateimaging device 100. Accordingly, reduction in color mixture andimprovement of sensitivity can be realized in the solid-state imagingdevice 100. Further, the color filters 15 can be formed by selfalignment in a manner to be based on the light shielding film 17 whichis formed between pixels, enabling improvement of overlay accuracybetween the light shielding film 19 and the color filters 15.

Second Embodiment

Next, a solid-state imaging device 200 according to a second embodimentwill be described. Since the solid-state imaging device 200 has the sameconfiguration as the solid-state imaging device 100 in FIG. 2 except forplanarized color filters 25, the same components are denoted with thesame reference characters and description thereof will be omitted.

The solid-state imaging device 200 shown in FIG. 4 has color filters 25disposed in the same layer as the light shielding film 17 as well as anadhesive film 29 formed on the side walls of the light shielding film 17and on the insulator film 18.

The adhesive film 29 is formed between the light shielding film 17 andcolor filters 25. The adhesive film 29 is formed on the side walls ofthe light shielding film 17 but not formed on one surface orthogonal tothe side walls of the light shielding film 17. The adhesive film 29 isalso formed on the insulator film 18. The adhesive film 29 is the sameas the adhesive film 19 in FIG. 2 in terms of its structure andmaterial, except for its shape.

The color filters 25 are planarized and formed in the same layer as thelight shielding films 17.

The solid-state imaging device 200 has the adhesive film 29 and colorfilters 25 sequentially formed in the apertures formed by the lightshielding film 17 and insulator film 18. The adhesive film 29 is formednot only between the color filters 25 and insulator film 18 but alsobetween the side walls of the light shielding film 17 and the colorfilters 25.

Next, a method of manufacturing the solid-state imaging device 200 willbe described. The steps until the color filters 25 are formed are thesame as those in FIGS. 3A to 3E and therefore description thereof willbe omitted.

In FIGS. 3A to 3F, the color filters 15 are formed before themicrolenses 16 are formed. Instead, in the present embodiment, the colorfilters 25 are formed and planarized before the microlenses 16 areformed, as shown in FIGS. 5A and 5B.

As shown in FIG. 5A, after the color filters 25 are formed, the colorfilters 25 are planarized by CMP, dry etching, or the like. Here, thecolor filters 25 are planarized until the surfaces of the lightshielding film 17 are exposed. The adhesive film 29 formed on onesurface of the light shielding film 17 is also etched accordingly.Alternatively, etching may be stopped when the adhesive films 29 isstill left. In this case, the adhesive film 29 would be formed on theside walls of the light shielding film 17 and on the insulator film 18.

As shown in FIG. 5B, after the color filters 25 are planarized,microlens 16 are formed on the color filters 25.

As described above, the solid-state imaging device 200 according to thepresent embodiment can improve image quality with an improvedirregularity/shading/sensitivity ratio because of the planarized colorfilters 25, and can suppress the detachment of color filters by theadhesive film 29 provided between the color filters 25 and the lightshielding film 17 and between the color filters 25 and the insulatorfilm 18. Further, the color filters 25 are embedded in the layer of thelight shielding film 17, enabling reduction in height of the solid-stateimaging device 200. Further, the color filters 25 can be formed by selfalignment in a manner to be based on the light shielding film 17 whichis formed between pixels, enabling improvement of overlay accuracybetween the light shielding film 17 and the color filters 25.

Third Embodiment

Next, a solid-state imaging device 300 according to a third embodimentwill be described. Since the solid-state imaging device 300 has the sameconfiguration as the solid-state imaging device 100 in FIG. 2 except forthe shape of an adhesive film 39, the same components are denoted withthe same reference characters and description thereof will be omitted.

The solid-state imaging device 300 shown in FIG. 6 has an adhesive film39 formed between one surface of the light shielding film 17 and thecolor filters 15.

The adhesive film 39 is formed on a part of the light shielding film 17,i.e., on one surface thereof in this embodiment, but not formed on theside walls of the light shielding film 17 and on the insulator film 18.The material and other features of the adhesive film 39 are the same asthose of the adhesive film 19 shown in FIG. 2 and therefore descriptionthereof will be omitted.

Next, a method of manufacturing the solid-state imaging device 300 willbe described. The steps until the film 171 is formed are the same asthose in FIGS. 3A and 3B and therefore description thereof will beomitted.

After the film 171 is formed, the adhesive film 39 is deposited on thefilm 171 as shown in FIG. 7A. Subsequently, the film 171 is patterned bylithography to form in the film 171 apertures for pixels 112 and thenthe film 171 and the adhesive film 39 are etched to form a lightshielding film 17 and the adhesive film 39 (FIG. 7B).

Next, color filters 15 are formed (FIG. 7C) and microlenses 16 areformed on the color filters 15 (FIG. 7D).

Since the adhesive film 39 is not provided between the insulator film 18and the color filters 15 as described above, the solid-state imagingdevice 300 according to the present embodiment can be reduced in heightcompared with the solid-state imaging device 100 shown in FIG. 2. Withthis, the solid-state imaging device 300 can achieve the reduction incolor mixture and improve the sensitivity. The adhesive film 39 providedbetween one surface of the light shielding film 17 and the color filters15 can suppress the detachment of color filters. Further, the colorfilters 15 can be formed by self alignment in a manner to be based onthe light shielding film 17 which is formed between pixels, enablingimprovement of overlay accuracy between the light shielding film 17 andthe color filters 15.

The solid-state imaging device 300 according to the present embodimentis particularly useful when the adhesion of the light shielding film 17to the color filters 15 is inferior to the adhesion of the insulatorfilm 18 to the color filters 15.

Fourth Embodiment

Next, a solid-state imaging device 400 according to a fourth embodimentwill be described. Since the solid-state imaging device 400 has the sameconfiguration as the solid-state imaging device 100 in FIG. 2 except forthe shape of an insulation film 48, the same components are denoted withthe same reference characters and description thereof will be omitted.

As shown in FIG. 8, the solid-state imaging device 400 includes theinsulator film 48 with recesses.

The insulator film 48 has projections and recesses on one surface. Alight shielding film 17 is formed on the projections and an adhesivefilm 19 and color filters 15 are formed in the recesses. Thus, thesolid-state imaging device 400 has the adhesive film 19 and the colorfilters 15 embedded in the insulator film 48.

Next, a method of manufacturing the solid-state imaging device 400 willbe described. The steps until the film 171 is formed are the same asthose in FIGS. 3A and 3B and therefore description thereof will beomitted.

After the film 171 is formed, the film 171 is patterned by lithographyto form in the film 171 apertures for pixels 112 and then the film 171and the insulator film 48 are etched as shown in FIG. 9A. The totaletching depth of the light shielding film 17 and insulator film 48 isapproximately 100 nm to 1 μm. In this manner, the light shielding film17 and the insulator film 48 with recesses are formed.

After the light shielding film 17 is formed, an adhesive film 19 isdeposited or applied using a spin coating process, spray coatingprocess, slit coating process, or the like as shown in FIG. 9B. Then,color filters 15 having a thickness of approximately 100 nm to 1 μm areformed (FIG. 9C) and microlenses 16 are formed on the color filters 15(FIG. 9D).

As described above, the solid-state imaging device 400 according to thepresent embodiment has the insulator film 48 with recesses and the colorfilters 15 embedded within the recesses. This allows the solid-stateimaging device 400 to be reduced in height while retaining the desiredthickness of the color filters 15 without increasing the thickness ofthe light shielding film 17. With this, the solid-state imaging device400 can achieve the reduction in color mixture and improve thesensitivity. The adhesive film 19 provided between the light shieldingfilm 17 and the color filters 15 can suppress the detachment of colorfilters 15. Further, the color filters 15 can be formed by selfalignment in a manner to be based on the light shielding film 17 whichis formed between pixels, enabling improvement of overlay accuracybetween the light shielding film 17 and the color filters 15.

To etch the insulator film 48 in FIG. 9A, isotropic etching may be usedto form rounded recesses in the insulator film 48. In this case, theoptical waveguide formed by the light shielding film 17 and adhesivefilm 19 would form a convex lens projecting downward in the lowerportion thereof which allows the incident light from the microlens 16 tobe further converged.

Fifth Embodiment

Next, a solid-state imaging device 500 according to a fifth embodimentwill be described. Since the solid-state imaging device 500 has the sameconfiguration as the solid-state imaging device 400 in FIG. 8 except fora planarized color filter 25, the same components will be denoted withthe same reference characters and description thereof will be omitted.

The solid-state imaging device 500 shown in FIG. 10 has color filters 25disposed in the same layer as the light shielding film 17 and anadhesive film 29 formed on the side walls of the light shielding film 17and on the insulator film 18.

The adhesive film 29 is formed between the light shielding films 17 andcolor filters 25. The adhesive film 29 is formed on the side walls ofthe light shielding film 17 but not formed on one surface orthogonal tothe side walls of the light shielding film 17. The adhesive film 29 isalso formed on the insulator film 18. The adhesive film 29 is the sameas the adhesive film 19 in FIG. 2 in terms of its structure andmaterial, except for its shape.

The color filters 25 are planarized and formed in the same layer as thelight shielding films 17.

The solid-state imaging device 500 has the adhesive film 29 and thecolor filters 25 sequentially formed in the apertures formed by thelight shielding film 17 and insulator film 18. The adhesive film 29 isformed not only between the color filters 25 and insulator film 18 butalso between the side walls of the light shielding film 17 and the colorfilters 25.

Next, a method of manufacturing the solid-state imaging device 500 willbe described. The steps until the color filters 25 are formed are thesame as those in FIGS. 9A to 9C and therefore description thereof willbe omitted.

In FIGS. 9A to 9D, after the color filters 15 are formed, themicrolenses 16 are formed. Instead, in the present embodiment, the colorfilters 25 are formed and planarized before the microlenses 16 areformed as shown in FIGS. 11A and 11B.

As shown in FIG. 11A, after the color filters 25 are formed, the colorfilters 25 are planarized by CMP, dry etching, or the like. Here, thecolor filters 25 are planarized until the surfaces of the lightshielding film 17 are exposed as shown in FIG. 11A. The adhesive film 29formed on one surface of the light shielding film 17 are also etchedaccordingly. Alternatively, etching may be stopped when the adhesivefilm 29 is still left. In this case, the adhesive film 29 would beformed on the side walls of the light shielding film 17 and on theinsulator film 18.

As shown in FIG. 11B, after the color filters 25 are planarized,microlens 16 are formed on the color filters 25.

As described above, the solid-state imaging device 500 according to thepresent embodiment can improve image quality with an improvedirregularity/shading/sensitivity ratio, etc., because of the planarizedcolor filters 25, and can suppress the detachment of color filters bythe adhesive film 29 provided between the color filters 25 and the lightshielding film 17 and between the color filters 25 and the insulatorfilm 18. Further, the color filters 25 can be formed by self alignmentin a manner to be based on the light shielding film 17 which is formedbetween pixels, enabling improvement of overlay accuracy between thelight shielding film 17 and the color filters 25.

Sixth Embodiment

Next, a solid-state imaging device 600 according to a sixth embodimentwill be described. Since the solid-state imaging device 600 has the sameconfiguration as the solid-state imaging device 400 in FIG. 8 except forthe shape of the adhesive film 39, the same components are denoted withthe same reference characters and description thereof will be omitted.

The solid-state imaging device 600 shown in FIG. 12 has an adhesive film39 formed between one surface of the light shielding film 17 and thecolor filters 15.

The adhesive film 39 is formed on a part of the light shielding film 17,i.e., on one surface thereof in the present embodiment, but not formedon the side walls of the light shielding film 17 and on the insulatorfilm 18. The material and other features of the adhesive film 39 are thesame as those of the adhesive film 19 shown in FIG. 2 and thereforedescription thereof will be omitted.

Next, a method of manufacturing the solid-state imaging device 600 willbe described. The steps until the adhesive film 39 is deposited on thefilm 171 are the same as those up to the step shown in FIG. 7A andtherefore description thereof will be omitted.

After the adhesive film 39 is formed, the film 171 is patterned bylithography to form in the film 171 apertures for pixels 112 and thenthe film 171 and the insulator film 48 are etched as shown in FIG. 13A.Then, color filters 15 having a thickness of approximately 100 nm to 1μm are formed (FIG. 13B) and microlenses 16 are formed on the colorfilters 15 (FIG. 13C).

Since the adhesive film 39 is not provided between the insulator film 18and the color filters 15 as described above, the solid-state imagingdevice 600 according to the present embodiment can be reduced in heightcompared with the solid-state imaging device 400 shown in FIG. 8. Withthis, the solid-state imaging device 600 can achieve the reduction incolor mixture and improve the sensitivity. The adhesive film 39 providedbetween one surface of the light shielding film 17 and the color filters15 can suppress the detachment of color filters. Further, the colorfilters 15 can be formed by self alignment in a manner to be based onthe light shielding film 17 which is formed between pixels, enablingimprovement of overlay accuracy between the light shielding film 17 andthe color filters 15.

The solid-state imaging device 600 according to the present embodimentis particularly useful when the adhesion of the light shielding films 17to the color filters 15 is inferior to the adhesion of the insulatorfilm 18 to the color filters 15.

Seventh Embodiment

Next, a solid-state imaging device 700 according to a seventh embodimentwill be described.

As shown in FIG. 14, the solid-state imaging device 700 has pixels 112each having a photoelectric conversion element 11 for convertingincident light to an electric signal, color filters 15 associated withthe pixels 112 and having a plurality of color filter components,microlenses 16 for converging the incident light through the colorfilters 15 onto the photoelectric conversion elements 11, and a lightshielding film 17 provided on the insulator film 48 between the colorfilter components of the color filters 15 embedded in the insulator film48.

As the insulator film 48, a material having a high adhesion to the colorfilters 15 is selected.

Since the solid-state imaging device 700 has the same configuration asthe solid-state imaging device 400 in FIG. 8 except for the lack of theadhesive film 19, the same components are denoted with the samereference characters and description thereof will be omitted.

Next, a method of manufacturing the solid-state imaging device 700 willbe described. The steps until the light shielding film 17 and insulatorfilm 48 are formed by etching the film 171 and insulator film 48 are thesame as those up to the step shown in FIG. 9A and therefore descriptionthereof will be omitted.

After the light shielding film 17 is formed, color filters 15 having athickness of approximately 100 nm to 1 μm are formed as shown in FIG.15A without any adhesive film therebetween. Next, microlenses 16 areformed on the color filters 15 as shown in FIG. 15B.

As described above, the solid-state imaging device 700 according to thepresent embodiment has the insulator film 48 with recesses for embeddingthe color filters 15 therein. Selecting as the insulator film 48 amaterial having a high adhesion to the color filters 15 can furtherimprove the adhesion of the insulator film 48 to the color filters 15and thus suppress the detachment of color filters 15.

Embedding the color filters 15 in the insulator film 48 allows thesolid-state imaging device 400 to be reduced in height while retainingthe desired thickness of the color filters 15 without increasing thethickness of the light shielding film 17. With this, the solid-stateimaging device 400 can achieve the reduction in color mixture andimprove the sensitivity. Further, the color filters 15 can be formed byself alignment in a manner to be based on the light shielding film 17which is formed between pixels, enabling improvement of overlay accuracybetween the light shielding film 17 and the color filters 15.

Eighth Embodiment

Next, a solid-state imaging device 800 according to an eighth embodimentwill be described. Since the solid-state imaging device 800 has the sameconfiguration as the solid-state imaging device 700 in FIG. 14 exceptfor a planarized color filter 25, the same components are denoted withthe same reference characters and description thereof will be omitted.

The solid-state imaging device 800 shown in FIG. 16 has color filters 25disposed in the same layer as the light shielding film 17.

Next, a method of manufacturing the solid-state imaging device 800 willbe described. The steps until the color filters 25 are formed are thesame as those up to the step shown in FIG. 15A and therefore descriptionthereof will be omitted.

In FIGS. 15A and 15B, after the color filters 15 are formed, themicrolenses 16 are formed. Instead, in the present embodiment, the colorfilters 25 are formed and planarized before the microlenses 16 areformed as shown in FIGS. 17A and 17B.

As shown in FIG. 17A, after the color filters 25 are formed, the colorfilters 25 are planarized by CMP, dry etching, or the like. Here, thecolor filters 25 are planarized until the surfaces of the lightshielding film 17 are exposed.

After the color filters 25 are planarized, microlenses 16 are formed onthe color filters 25 as shown in FIG. 17B.

The solid-state imaging device 800 according to the present embodimenthas the planarized color filters 25 as described above and can thereforeimprove an irregularity/shading/sensitivity ratio, etc., andconsequently improve image quality. The solid-state imaging device 800has also recesses formed in the insulator film 48 for embedding thecolor filters 25. Selecting as the insulator film 48 a material having ahigh adhesion to the color filters 25 can further improve the adhesionof the insulator film 48 to the color filters 25 and thereby suppressthe detachment of color filters 25. Further, the color filters 25 can beformed by self alignment in a manner to be based on the light shieldingfilm 17 which is formed between pixels, enabling improvement of overlayaccuracy between the light shielding film 17 and the color filters 25.

Ninth Embodiment

Next, a solid-state imaging device 900 according to a ninth embodimentwill be described. Since the solid-state imaging device 900 has the sameconfiguration as the solid-state imaging device 100 in FIG. 2 except foran oxide film 40 provided between the adhesive film 19 and lightshielding film 17, the same components are denoted with the samereference characters and description thereof will be omitted.

As shown in FIG. 18, the solid-state imaging device 900 has the oxidefilm 40 formed on surfaces (one surface and side walls) of the lightshielding film 17 and on the insulator film 18. An adhesive film 19 isdeposited on the oxide film 40. The adhesive film 19 is formed from amaterial having good adhesion to the oxide film 40. It is favorable toform the oxide film 40 and the adhesive film 19 in such thicknesses thatat least part of the color filter 15 is formed to be positioned lowerthan the light shielding film 17 which is formed to correspond to eachpixel. That is, the oxide film 40 and the adhesive film 19 are formedsuch that the total film thickness T3 of the oxide film 40 and theadhesive film 19 satisfies T3<T1, where T1 is the film thickness of thelight shielding film 17.

Examples of the material of the oxide film 40 include a SiO₂ film, aP—SiO film, a HDP-SiO film, and the like which are formed by using atleast any material gas made of silicon hydroxide (Si_(n)H_(2n+2)),alkylsilane (SiH_(n)R_(4-n), SiR₄), alkoxysilane (SiH_(n)(OR)_(4-n),Si(OR)₄, Si(OR)₂(OR′)₂), or polysiloxane, and an oxidizing agent.Instead of the oxide film 40, a nitride film may be employed.

Here, the oxide film 40 and the adhesive film 19 may be formed bypatterning and etching using lithography so as to cover only the uppersurface and the side walls of the light shielding film 17.

Next, a method of manufacturing the solid-state imaging device 900 willbe described. The steps until the light shielding film 17 is formed arethe same as those in FIGS. 3A to 3C and therefore description thereofwill be omitted.

As shown in FIG. 19A, after the light shielding film 17 is formed, anoxide film 40 is deposited or applied using a spin coating process,spray coating process, slit coating process, or the like. Next, anadhesive film 19 is deposited on the oxide film 40 using a spray coatingprocess, slit coating process, or the like (FIG. 19B). Next, colorfilters 15 are formed on the adhesive film 19 (FIG. 19C) and microlenses16 are formed on the color filters 15 (FIG. 19D).

As described above, the adhesive film 19 can be deposited on the oxidefilm 40 as in the solid-state imaging device 900 according to thepresent embodiment. In spite of the oxide film 40 thus formed, thedetachment of color filters can be suppressed because the adhesive film19 and oxide film 40 are formed between the color filters 15 and thelight shielding film 17. Further, the color filters 15 can be formed byself alignment in a manner to be based on the light shielding film 17which is formed between pixels, enabling improvement of overlay accuracybetween the light shielding film 17 and the color filters 15.

Tenth Embodiment

Next, a solid-state imaging device 1000 according to a tenth embodimentwill be described. Since the solid-state imaging device 1000 has thesame configuration as the solid-state imaging device 900 in FIG. 18except for an oxide film 50 formed on one surface of the light shieldingfilm 17, the same components are denoted with the same referencecharacters and description thereof will be omitted.

As shown in FIG. 20, the solid-state imaging device 1000 has the oxidefilm 50 formed on one surface of the light shielding film 17. Anadhesive film 19 is deposited on the oxide film 50 and insulator film 18and on the side walls of the light shielding film 17. The adhesive film19 is made of a material having good adhesion to the oxide film 50 andlight shielding film 17. The oxide film 50 is formed on one surface ofthe light shielding film 17 but, unlike the solid-state imaging device900 in FIG. 18, not formed on the insulator film 18 and on the sidewalls of the light shielding film 17.

Next, a method of manufacturing the solid-state imaging device 1000 willbe described. The steps until the film 171 is formed are the same asthose in FIGS. 3A and 3B and therefore description thereof will beomitted.

After the film 171 is formed, an oxide film 50 is deposited on the film171 as shown in FIG. 21A. Subsequently, the film 171 is patterned bylithography to form in the film 171 apertures for pixels 112 and thenthe film 171 and oxide film 50 are etched to form a light shielding film17 and the oxide film 50.

Next, an adhesive film 19 is deposited or applied on the light shieldingfilm 17 and oxide film 50 using a spin coating process, spray coatingprocess, slit coating process, or the like (FIG. 21B). Next, colorfilters 15 are formed (FIG. 21C) and microlenses 16 are formed on thecolor filters 15 (FIG. 21D).

The lack of the oxide film 50 between the insulator film 18 and thecolor filters 15 as described above allows the solid-state imagingdevice 1000 according to the present embodiment to be reduced in heightcompared with the solid-state imaging device 900 shown in FIG. 18. Withthis, the solid-state imaging device 1000 can achieve the reduction incolor mixture and improve the sensitivity. The adhesive film 19 providedbetween one surface of the light shielding film 17 and the color filters15 can suppress the detachment of color filters 15. Further, the colorfilters 15 can be formed by self alignment in a manner to be based onthe light shielding film 17 which is formed between pixels, enablingimprovement of overlay accuracy between the light shielding film 17 andthe color filters 15.

In the ninth and tenth embodiments, the oxide film 40, 50 is provided inthe solid-state imaging device 100 in FIG. 2. Instead, the oxide film40, 50 may be provided in the solid-state imaging device 400 in FIG. 8.

Eleventh Embodiment

Next, a solid-state imaging device 1100 according to an eleventhembodiment will be described. Since the solid-state imaging device 1100has the same configuration as the solid-state imaging device 100 in FIG.2 except for the shape of the light shielding film, the same componentswill be denoted with the same reference characters and descriptionthereof will be omitted.

Referring now to FIGS. 22A and 22B, the solid-state imaging device 1100will be described in detail. FIG. 22A is a sectional view of thesolid-state imaging device 1100 along a line in a side direction acrossthe pixel 112. FIG. 22B is a sectional view of the solid-state imagingdevice 1100 along a line in a diagonal direction across the pixel 112.

The light shielding film includes first light shielding portions 271 andsecond light shielding portions 272. The first light shielding portions271 and the second light shielding portions 272 are provided between thecolor filter components of the color filters 15. The distance from thepixel 112 to the surface of the first light shielding portion 271closest to the microlens 16 is longer than that of the second lightshielding portion 272. More specifically, a relationship d1>d2 (d1 andd2 are nonzero) is established, where d1 is the distance from the pixel112 to the surface of the first light shielding portion 271 closest tothe microlens 16 and d2 is the distance from the pixel 112 to thesurface of the second light shielding portion 272 closest to themicrolens 16.

In the present embodiment, the region extending from one dot-and-dashline to another dot-and-dash line in FIGS. 22A and 22B in which a pixel112, a color filter component of the color filter 15, and a microlens 16are contained is referred to as a pixel region. The dot-and-dash lineindicating the boundary of each pixel region in FIGS. 22A and 22B isreferred to as a pixel boundary. The pixel region of the solid-stateimaging device 1100 according to the present embodiment has a squareplane; the segment passing through the midpoints of the opposite sidesof this plane is referred to as being in the side direction across thepixel region, while the segment extending between the opposing cornersof the plane is referred to as being in the diagonal direction acrossthe pixel region.

Referring now to FIGS. 23A to 23C, the light shielding film according tothe present embodiment will be described. FIG. 23A is a plan view of thelight shielding film. FIG. 23B is a cross-sectional view of the lightshielding film and insulator film 18 along the line XXIIIB-XXIIIB (inthe side direction across the pixel region) in FIG. 23A; FIG. 23C is across-sectional view of the light shielding film and insulator film 18along the line XXIIIC-XXIIIC (in the diagonal direction across the pixelregion) in FIG. 23A.

The light shielding film is formed on the pixel boundaries, i.e., aroundthe pixel region and between the color filter components of the colorfilters 15. The light shielding film is formed in the form of a latticeas shown in FIG. 23A.

The light shielding film includes first light shielding portions 271formed on the side portions of the pixel regions and second lightshielding portions 272 formed at the corner portions of the pixelboundaries.

The first light shielding portions 271 are formed on the side portionsof the lattice-shaped light shielding film. The first light shieldingportion 271 has a predetermined film thickness. The pixel region issquare as viewed from the microlens 16. A region having a rectangularshape with a certain width and four sides is referred to as a sideportion of the pixel region. The first light shielding portions 271 areformed on the side portions of the pixel region between the color filtercomponents of the color filters 15. The first light shielding portion271 has an end surface (first end surface) being in contact with themicrolens 16 and another end surface (second end surface) opposing thefirst end surface. The first light shielding portion 271 has asubstantially tapered shape having a predetermined film thickness d1,with the first end surface being narrower than the second end surface.

The second light shielding portions 272 are formed at the intersectionsin the lattice-shaped light shielding film. The second light shieldingportion 272 is cruciform as viewed from above and has a predeterminedfilm thickness that is thinner than the film thickness of the firstlight shielding portion 271. The pixel region is square as viewed fromthe microlens 16. A region including a corner of the square and having acertain width is referred to as a corner portion of the pixel region.The second light shielding portions 272 are formed on the same plane asthe color filters 15, on the corner portions of the pixel regions. Thesecond light shielding portion 272 includes an end surface (first endsurface) being in contact with the microlens 16 and another end surface(second end surface) opposing the first end surface.

In the solid-state imaging device 1100 according to the presentembodiment, the light shielding film is formed on the insulator film 18toward the back side of the substrate 111. Consequently, the distancefrom the front side of the pixel 112 to the end surface of the firstlight shielding portion 271 toward the microlens 16 is equal to the sumof the film thickness of the first light shielding portion 271 and thefilm thickness of the insulator film 18. The distance from the frontside of the pixel 112 to the end surface of the second light shieldingportion 272 toward the microlens 16 is equal to the sum of the filmthickness of the second light shielding portion 272 and the filmthickness of the insulator film 18. Because the film thickness of theinsulator film 18 is fixed and the film thickness of the first lightshielding portion 271 is greater than the film thickness of the secondlight shielding portion 272, the distance d1 from the front side of thepixel 112 to the end surface of the first light shielding portion 271toward the microlens 16 is greater than the distance from the front sideof the pixel 112 to the end surface of the second light shieldingportion 272 toward the microlens 16.

Referring now to FIGS. 24A to 24F, a method of manufacturing thesolid-state imaging device 1100 according to the present embodiment willbe described. The steps until the insulator film 18 is formed are thesame as those for the solid-state imaging device 100 in FIG. 2 andtherefore description thereof will be omitted.

Parts (a) in FIGS. 24A to 24F are sectional views of the pixel regionalong a line in the side direction; parts (b) in FIGS. 24A to 24F aresectional views of the pixel region along a line in the diagonaldirection. The dot-and-dash lines in FIGS. 24A to 24F indicate theboundaries of the pixel regions.

As shown in FIG. 24A, a film 31 is formed on the insulator film 18. Thefilm 31 is made of a material that blocks incident light. When aconductive material, for example, is employed as the light shieldingfilm, aluminum, tungsten, or the like may be employed. When an organicmaterial is employed as the light shielding film, an organic filmcontaining carbon or titan black particles or any other material havingblack pigments scattered therein may be employed.

As shown in FIG. 24B, a first photoresist 32 is formed on the film 31.The first photoresist 32 has on the corner portions of the pixel regioncruciform apertures that are similar to, but wider than, those of thesecond light shielding portions 272 (see reference character A in part(b) in FIG. 24B).

The first photoresist 32 is used as the mask for dry etching theunderlying film 31 (see FIG. 24C). Here, as indicated by referencecharacter B in part (b) in FIG. 24C, the dry etching is stopped beforethe entire thickness of the film 31 is etched. With this, recesses areformed in the film 31.

Once the dry etching is completed, the first photoresist 32 is removedand a second photoresist 33 is formed on the film 31. The secondphotoresist 33 is formed on the side portions of the pixel regions in ashape similar to the first light shielding portion 271 and on the cornerportions of the pixel regions in a shape similar to the second lightshielding portion 272. The portions of the second photoresist 33 to beformed on the corner portions of the pixel regions are formed in therecesses in the film 31 (see reference character C in part (b) in FIG.24D).

The second photoresist 33 is employed as the mask for dry etching theunderlying film 31 as shown in FIG. 24E and then the second photoresist33 is removed as shown in FIG. 24F to form the first light shieldingportions 271 and second light shielding portions 272.

In this manner, photoresist patterning and dry etching are conductedtwice to form the first light shielding portions 271 and second lightshielding portions 272 with different thicknesses.

The methods of forming the adhesive film 19 and color filters 15 are thesame as those for the solid-state imaging device 100 in FIG. 2 andtherefore description thereof will be omitted.

Referring now to FIGS. 25A to 25F, a method of forming microlenses 16will be described. Parts (a) in FIGS. 25A to 25F are sectional views ofthe pixel region along a line in the side direction; parts (b) in FIGS.25A to 25F are sectional views of the pixel region along a line in thediagonal direction.

After the color filters 15 are formed as shown in FIG. 25A, a microlensmaterial 43 is formed on the color filters 15. As the microlensmaterial, polystyrene resin, novolac resin, copolymer resin containingany one of these resins and acrylic resin, or a resin containingaromatic rings as the side chains of the acrylic resin may be used.

As shown in FIG. 25B, a positive photoresist 44 is applied on themicrolens material 43. The positive photoresist 44 may contain novolacresin, for example, as the main component.

Next, the positive photoresist 44 is patterned for each pixel byphotolithography (FIG. 25C).

The patterned positive photoresist 44 is subjected to heat treatment ata temperature higher than its softening point to form lens-shapedpositive photoresists 44 (FIG. 25D). The line width of the positivephotoresist 44 is narrower in the side direction (W1) of the pixelregion than in the diagonal direction (W2).

The lens-shaped positive photoresists 44 are used as the masks for dryetching to transfer the lens-shaped patterns to the underlying microlensmaterial 43 (FIG. 25E). Since the line width of the positive photoresist44 is narrower in the side direction (W1) of the pixel region than inthe diagonal direction (W2), there is substantially no spacing betweenthe lenses adjacent in the side direction of the pixel region whilethere is spacing between the lenses adjacent in the diagonal direction.

For the solid-state imaging device 1100 according to the presentembodiment, etching is continued to eliminate the spacing between thelenses adjacent in the diagonal direction. As shown in FIG. 25F, afterthe spacing between the lenses adjacent in the side direction issubstantially eliminated, etching is continued to reduce the spacingbetween the lenses adjacent in the diagonal direction to virtually zero.When any spacing left between the adjacent microlenses 16 does notexceed 200 nm, it is sufficiently smaller than the light wavelength anddoes not affect the sensitivity of the solid-state imaging device.Accordingly, the adjacent microlenses 16 are substantially in contactwith each other and the spacing between the adjacent lenses isconsidered to be virtually zero.

When the microlenses 16 are formed as described above, the thickness h4of the side portions of the pixel boundary of the microlens 16 becomesgreater than the thickness h5 of the corner portions. More specifically,the microlenses 16 are formed such that the upper surfaces of themicrolenses 16 are located at the same level and the bottoms of themicrolenses 16 formed on the side portions are located at a lowerposition (positions closer to the color filters 15) than the bottoms ofthe microlenses 16 formed on the corner portions of the pixel regions(positions where adjacent microlenses 16 are brought into contact witheach other).

Referring now to FIGS. 26A to 26D, effects of making the film thicknessof the second light shielding portion 272 thinner than the filmthickness of the first light shielding portion 271 will be described.

FIGS. 26A and 26B are sectional views of the microlens 16, color filter15, light shielding film, and adhesive film 19 of the solid-stateimaging device 1100 according to the present embodiment.

FIGS. 26C and 26D illustrate solid-state imaging device with the filmthickness of the second light shielding portion 272 being equal to thefilm thickness of the first light shielding portion 271. The secondlight shielding portion 272 has the same configuration as in FIGS. 26Aand 26B except for the film thickness thereof.

In FIGS. 26A to 26D, the vertically incident light converged by themicrolens 16 is indicated by solid lines, while the obliquely incidentlight with the chief ray tilted is indicated by dashed lines.

As shown in FIGS. 26A and 26C, in the plane extending through the centerof the microlens 16 of the solid-state imaging device 1100 in parallelto the pixel boundaries (i.e., cross section of the pixel region in theside direction), the vertically incident light enters the color filter15 without being blocked by the first light shielding portions 271. Onthe other hand, the obliquely incident light is partially reflected offthe first light shielding portions 271.

As shown in FIG. 26D, in the plane extending through the center of themicrolens 16 of the solid-state imaging device 1100 and through thediagonal line across the pixel region (i.e., cross section of the pixelregion in the diagonal direction), the incident light is blocked by thesecond light shielding portions 272 and the so-called mechanicalvignetting occurs accordingly. Particularly, at the corner portions ofthe microlens 16, both the vertically incident light and obliquelyincident light are reflected off the light shielding films and therebythe optical sensitivity of the solid-state imaging device 1100 isdegraded.

The second light shielding portions 272 are formed by depositing a film171 on the insulator film 18, then forming a resist pattern bylithography, and dry-etching the resist pattern. The resist patternformed by lithography has openings with a rounded shape such that theapertures become planarly small (see FIG. 23A). The width in thediagonal direction (W2) of the second light shielding portion 272,therefore, becomes wider than the width in the side direction (W1).Since the line width W2 of the second light shielding portion 272becomes wider than the line width W1 of the first light shieldingportion 271, much of the light incident through the corner portions ofthe microlens 16 is reflected off the second light shielding portions272 and thereby the optical sensitivity of the solid-state imagingdevice 1100 is degraded.

When the film thickness of the second light shielding portion 272 isthinner than the film thickness of the first light shielding portion 271as shown in FIG. 26B, the incident light blocked by the second lightshielding portion 272 is decreased. Especially at the corner portions ofthe microlens 16, vertically incident light passes through the colorfilter 15 without being blocked by the light shielding film. Theobliquely incident light is partially reflected off the second lightshielding portions 272, but the obliquely incident light L that hasfailed to pass through the color filter 15 in FIG. 26D passes throughthe color filter 15.

In this manner, reducing the film thickness of the second lightshielding portion 272 can decrease the incident light reflected off thelight shielding film and thereby suppress the reduction in opticalsensitivity of the solid-state imaging device 1100. Not reducing thefilm thickness of the first light shielding portion 271 can reduce colormixture due to the leakage of incident light into the adjacentphotoelectric conversion elements 11.

Making the film thickness of the second light shielding portion 272thinner than the film thickness of the color filter 15 produces a regionin which the color filter 15 is not formed above the second lightshielding portion 272. This allows the corner portions of themicrolenses 16 to be formed in the layer of the color filters 15 asshown in FIG. 27. This means that the distance d3 from the surface ofthe color filter 15 toward the photoelectric conversion element 11 tothe corner portion of the microlens 16 can be made shorter than the filmthickness of the color filter 15 and thus a thinner microlens 16 can beformed.

The adhesive film 19 provided between the light shielding films and thecolor filters 15 suppresses the detachment of color filters 15.

In the eleventh embodiment, the film thickness is reduced at the cornerportions of the light shielding film in the solid-state imaging device100 according to the first embodiment. Instead, the film thickness maybe reduced at the corner portions of the light shielding film in thesolid-state imaging devices 200 to 1000 of the second to tenthembodiments.

Twelfth Embodiment

Referring now to FIG. 28, an exemplary application of the solid-stateimaging device 100 will be described in the twelfth embodiment of thepresent technology. FIG. 28 shows the solid-state imaging device 100applied in an electronic apparatus 1200. Examples of the electronicapparatus 1200 include a digital camera, a camera embedded in a mobiletelephone, a scanner, and a surveillance camera. Here described is acase in which the electronic apparatus 1200 is a digital camera.

The electronic apparatus 1200 according to the present embodiment has asolid-state imaging device 100, an optical lens 210, a shutter device211, a drive circuit 212, and a signal processing circuit 213.

The optical lens 210 focuses image light (incident light) from a subjectonto the imaging surface of the solid-state imaging device 100. Withthis, a signal charge is accumulated for a predetermined period in thesolid-state imaging device 100.

The shutter device 211 controls the light-irradiated period andlight-shielded period of the solid-state imaging device 100. The drivecircuit 212 supplies drive signals for controlling the transferoperation of the solid-state imaging device 100 and the shutteroperation of the shutter device 211.

According to the drive signal, the solid-state imaging device 100outputs the signal charge accumulated in the photoelectric conversionelement 11 as an electric signal.

The signal processing circuit 213 performs various signal processingoperations. The signal processing circuit 213 generates video signals byprocessing the electric signals output from the solid-state imagingdevice 100 and outputs the video signals to a memory or other storageunit, a monitor, or the like, which are not shown.

The electronic apparatus 1200 according to the present embodiment, whichis provided with the solid-state imaging device 100 according to thefirst embodiment as described above, can suppress the detachment ofcolor filters 15 and improve the image quality of the video signals.

In the above example, the solid-state imaging device 100 according tothe first embodiment is mounted on the electronic apparatus 1200.Alternatively, the solid-state imaging device according to any one ofthe second to tenth embodiments may be mounted on the electronicapparatus 1200.

Although in the above-mentioned embodiments, the CMOSback-illuminated-type solid-state imaging device is described as anexemplary solid-state imaging device, it will be appreciated by thoseskilled in the art that the present technology is not limited theretobut is also applicable to a CCD solid-state imaging device or afront-illuminated-type solid-state imaging device.

The embodiment of the present technology may also adopt any one of thefollowing configurations:

(1) A solid-state imaging device including:

pixels each having a photoelectric conversion element for convertingincident light to an electric signal;

color filters associated with the pixels and having a plurality of colorfilter components;

microlenses converging the incident light through the color filters tothe photoelectric conversion elements;

a light shielding film disposed between the color filter components ofthe color filters; and

a nonplanarized adhesive film provided between the color filters and thelight shielding film.

(2) The solid-state imaging device according to item (1), wherein thecolor filters are planarized.

(3) The solid-state imaging device according to item (1) or (2), whereinthe adhesive film is provided between one surface of the light shieldingfilm and the color filters.

(4) The solid-state imaging device according to any one of items (1) to(3), further including:

an insulator film between the photoelectric conversion elements and thecolor filters;

wherein the color filters are embedded in the insulator film.

(5) The solid-state imaging device according to any one of items (1) to(4), wherein an oxide film is provided between the adhesive film and thelight shielding film.

(6) The solid-state imaging device according to item (5), wherein theoxide film is provided on one surface of the light shielding film.

(7) The solid-state imaging device according to any one of items (1) to(6),

wherein the light shielding film includes

-   -   first light shielding portions formed on side portions of the        color filter components, and    -   second light shielding portions formed at corner portions of the        pixel regions,

wherein a distance from the front side of the pixel to an end surface ofthe second light shielding portion toward the microlens is shorter thana distance from the front side of the pixel to an end surface of thefirst light shielding portion toward the microlens.

(8) A method of manufacturing a solid-state imaging device, the methodincluding:

forming pixels each having a photoelectric conversion element forconverting incident light to an electric signal;

forming a light shielding film to be provided between a plurality ofcolor filter components of color filters;

depositing a nonplanarized adhesive film on the light shielding film;

forming the color filters on the adhesive film between the lightshielding films; and

forming on the color filters microlenses converging the incident lightthrough the color filters onto the photoelectric conversion elements.

(9) An electronic apparatus including:

a solid-state imaging device including

-   -   pixels each having a photoelectric conversion element for        converting incident light to an electric signal,    -   color filters associated with the pixels and having a plurality        of color filter components,    -   microlenses converging the incident light through the color        filters to the photoelectric conversion elements,    -   a light shielding film disposed between the color filter        components of the color filters, and    -   a nonplanarized adhesive film provided between the color filters        and the light shielding film; and

an optical lens guiding the incident light to the photoelectricconversion elements; and

a signal processing circuit processing the electric signal.

Finally, each of the above embodiments is merely an example of thepresent technology and the present technology is not limited to any oneof the above embodiments. It should be understood by those skilled inthe art that various modifications may occur depending on design andother factors insofar as they are within the scope of the presenttechnology.

The present disclosure contains subject matter related to that disclosedin Japanese Priority Patent Application JP 2011-055631 filed in theJapan Patent Office on Mar. 14, 2011 and Japanese Priority PatentApplication JP 2012-044006 filed in the Japan Patent Office on Feb. 29,2012, the entire contents of which are hereby incorporated by reference.

What is claimed is:
 1. An imaging device comprising: a plurality ofphotoelectric conversion elements; a plurality of color filtercomponents disposed over the plurality of the photoelectric conversionelements and including a first color filter component and a second colorfilter component adjacent to the first color filter component a lightshielding portion, at least a part of the light shielding portiondisposed between the first color filter component and the second colorfilter component in a cross-section view; and an adhesive film, at leasta part of the adhesive film disposed between the first color filtercomponent and the light shielding portion in the cross-section view,wherein a surface of the adhesive film facing to the first and secondcolor filter components is nonplanar, and wherein a thickness of theadhesive film is less than a thickness of the light shielding portion inthe cross-section view.
 2. The imaging device according to claim 1,wherein the plurality of photoelectric conversion elements includes afirst photoelectric conversion element corresponding to the first colorfilter component, and a second photoelectric conversion elementcorresponding to the second color filter component.
 3. The imagingdevice according to claim 1, wherein the first and second color filtercomponents are planarized.
 4. The imaging device according to claim 1,wherein the adhesive film is disposed between one surface of the lightshielding film and the color filter components.
 5. The imaging deviceaccording to claim 1, further comprising: an insulator film between thephotoelectric conversion elements and the color filter components. 6.The imaging device according to claim 1, wherein an oxide film isdisposed between the adhesive film and the light shielding portion. 7.The imaging device according to claim 6, wherein the oxide film isdisposed on one surface of the light shielding portion.
 8. The imagingdevice according to claim 6, wherein wherein the oxide film includes afilm selected from the group consisting of an SiO₂ film, a P—SiO film,or an HDP-SiO film.
 9. The imaging device according to claim 1, whereinmicrolenses are disposed directly on corresponding ones of the colorfilter components.
 10. The imaging device according to claim 1, furthercomprising: a first substrate having a first side as a light incidentside, and a second side opposite to the first side, wherein the firstsubstrate includes the plurality of photoelectric conversion element.11. The imaging device according to claim 10, wherein the thickness ofthe first substrate is 3-5 μm.
 12. The imaging device according to claim10, further comprising: a plurality of transistors disposed at thesecond side of the first substrate.
 13. The imaging device according toclaim 12, wherein the plurality of transistors comprises a transfertransistor associated with the photoelectric conversion element.
 14. Theimaging device according to claim 12, wherein the plurality oftransistors comprises a reset transistor and an amplificationtransistor.
 15. The imaging device according to claim 14, wherein theplurality of transistors further comprises a select transistor coupledto the amplification transistor.
 16. The imaging device according toclaim 12, further comprising: a drive circuit configured to drive theplurality of transistors; and a column signal processing circuit coupledto a signal line and configured to perform correlated double sampling ofan electric signal.
 17. The imaging device according to claim 12,wherein a wiring layer is disposed adjacent to the second side of thefirst substrate.
 18. The imaging device according to claim 17, whereinthe wiring layer comprises a signal line coupled to at least onetransistor of the plurality of transistors.
 19. The imaging deviceaccording to claim 17, wherein the wiring layer is disposed between thefirst substrate and a second substrate.
 20. The imaging device accordingto claim 1, further comprising: an element separation region disposedbetween adjacent ones of the photoelectric conversion elements.